Customization 
Premium workspaces have the option to set up page- and folder- level security. These security controls allow the workspace administrator to set granular access controls on every page or folder of the workspace.
Setting access levels
What are access controls?
For workspaces with a large number of editors, it may not be sufficient to distribute the administrative password publicly; malicious editors may be able to go in and delete pages and files, ruining users' work. Access controls let users whose needs go beyond a single-password solution offer several different levels of access, each with their own password: Admin, Editor, Writer, and Reader.
Admins
As the workspace's creator, you are the admin. As the admin, you are the god of your workspace. You can delete pages and change access levels for Editors, Writers, and Readers. Admins are the only users who have access to the workspace's Settings page.
Editors
Editors are trusted helpers who are super-privileged Writers. They can delete pages and files, including revisions and revision histories. Editors should be highly trusted, since they can delete your data irrevocably.
Writers
"Writer" is the recommended default for sharing access to your workspace. Writers can edit pages and revert pages to previous versions. They can also upload new files and create new pages. They cannot delete pages, files, or folders. Writers don't need to be super-trusted, since they cannot perform any action that cannot be undone.
Readers
Readers cannot make any modifications at all to a workspace. They only can read the pages, RSS feeds, and files. They can see page revision histories and diffs. Readers don't need to log into a public workspace.
Folder security
Folder security is a premium workspace feature. To set folder security, click on the folder and then the "Folder Security" button. You can set custom security or make a workspace folder public on a private workspace. For more information, take a look at Organizing Your Workspace.
Page security
Page security is a premium workspace feature. To set page security, click the "Page Security" icon on your workspace page. You can set custom security, choose to hide or lock pages, or you can make a page public on a private workspace. For more information, take a look at Page Security Settings.
Can I use IP restriction on my workspace?
A great way to ensure the security of your workspace is to use IP restriction. This means that only computers using a certain IP address will be allowed (IP whitelisting) or denied (IP blacklisting) access to your workspace. IP restriction is part of our business premium pricing plans. To find out more information about adding IP whitelisting or blacklisting to your workspace contact our sales team. Once you have IP restrictions available on your workspace, simply go to "Settings" and then click on the "IP restriction" link. You can find more information on using IP restriction here.
This feature has a video tutorial
This feature is new/improved